Messages in this thread | | | Date | Mon, 27 Jul 2020 16:13:37 +0200 | From | Christian Brauner <> | Subject | Re: bpfilter logging write errors in dmesg |
| |
On Mon, Jul 27, 2020 at 03:28:55PM +0200, Christoph Hellwig wrote: > On Mon, Jul 27, 2020 at 12:46:36PM +0200, Christian Brauner wrote: > > Hey Christoph, > > > > Seems that commit > > 6955a76fbcd5 ("bpfilter: switch to kernel_write") > > causes bpfilter to spew these useless messages in dmesg? > > > > [ 26.356824] Started bpfilter > > [ 26.357059] bpfilter: write fail -22 > > [ 26.396244] Started bpfilter > > [ 26.396325] bpfilter: Loaded bpfilter_umh pid 637 > > [ 26.396542] bpfilter: write fail -22 > > [ 26.409588] bpfilter: Loaded bpfilter_umh pid 638 > > [ 26.410790] Started bpfilter > > [ 26.410960] bpfilter: write fail -22 > > [ 26.445718] Started bpfilter > > [ 26.445799] bpfilter: Loaded bpfilter_umh pid 640 > > [ 26.445983] bpfilter: write fail -22 > > [ 26.451122] bpfilter: read fail 0 > > [ 26.496497] bpfilter: Loaded bpfilter_umh pid 648 > > [ 26.497889] Started bpfilter > > [ 26.750028] bpfilter: write fail -22 > > [ 26.768400] Started bpfilter > > [ 26.768496] bpfilter: Loaded bpfilter_umh pid 661 > > [ 26.768699] bpfilter: write fail -22 > > [ 26.806550] Started bpfilter > > [ 26.806616] bpfilter: Loaded bpfilter_umh pid 663 > > [ 26.864708] bpfilter: write fail -22 > > [ 26.872345] bpfilter: Loaded bpfilter_umh pid 666 > > [ 26.873072] Started bpfilter > > [ 26.873194] bpfilter: write fail -22 > > [ 27.295514] kauditd_printk_skb: 22 callbacks suppressed > > > > This is on a pure v5.8-rc7 via make bindep-pkg. I'm not using bpfilter > > in any shape or form afaict and haven't seen those messages before and > > this seems to be the last change I see. > > I don't see any of those on 5.8-rc, just: > > root@testvm:~# dmesg | grep bpf > [ 6.692550] bpfilter: Loaded bpfilter_umh pid 1849
Hm, odd
> > That debug patch below should help to pintpoint what is going on for > you:
Thanks for the debug patch! Applied and ran a kernel and I'm getting:
[ 21.919851] bpfilter: Loaded bpfilter_umh pid 619 [ 22.000229] rw_verify_area [ 22.000235] bpfilter: write fail -22 [ 22.014686] Started bpfilter
I'm also seeing some other failures later:
[ 236.898220] bpfilter: write fail -22 [ 236.899255] bpfilter: write fail -32 [ 236.922557] bpfilter: Loaded bpfilter_umh pid 1101 [ 236.923310] Started bpfilter [ 236.923521] rw_verify_area [ 236.923524] bpfilter: write fail -22 [ 236.925273] bpfilter: read fail 0 [ 236.945117] bpfilter: Loaded bpfilter_umh pid 1103 [ 236.945925] Started bpfilter [ 236.946123] rw_verify_area [ 236.946126] bpfilter: write fail -22 [ 236.947641] bpfilter: read fail 0 [ 236.968143] bpfilter: Loaded bpfilter_umh pid 1105 [ 236.968734] Started bpfilter [ 236.987777] rw_verify_area [ 236.987781] bpfilter: write fail -22 [ 236.990072] bpfilter: read fail 0
Seems I can trigger this via iptables:
[ 437.922719] bpfilter: write fail -22 [ 437.924488] bpfilter: read fail 0 root@g1-vm:~# iptables -S iptables v1.8.4 (legacy): can't initialize iptables table `filter': Bad address Perhaps iptables or your kernel needs to be upgraded.
I have CONFIG_IP_NF_IPTABLES=m CONFIG_IP6_NF_IPTABLES=m maybe I'm just missing another kernel option or something and I have no idea how this bpfilter thing and iptables relate to each other. So maybe it's not worth the effort and it's just my setup being broken somehow.
Christian
| |